It is common practice to employ a pair of electric bulbs or lamps in combination with an optical lens system in a railway and mass and/or rapid transit operation for signalling purposes. Currently, the dual-lamp receptacles are constructed by attaching two single contact bayonet candelabra sockets to an insulating board with machine screws and nuts. The sockets are mounted on soldered brackets and machined spacers hold the lamps in the desired position. A pair of standard binding posts are also mounted on the insulated board and a separate anti-turn device is applied to each post in order to prevent the threaded posts from turning. The complete lamp receptacle is mounted to the lens structure by a pair of cap screws and two machined spacers. This previous method of construction requires a myriad of small parts and machined pieces to form the receptacle that holds the sockets in place. It will be appreciated that the machining tolerances and allowances involved during the manufacture of the spacers will materially affect the distances from the lamps to the lens system which causes an inconsistency of the light intensity that exists between individual signal units. Thus, these previous signal units were expensive to machine as well as to assembly and were difficult to adjust to provide consistent light intensities.